A Synergy of Plasmonic D‐Band Holes and Dual Interfaces of Au Nanoparticles Boosts Photocatalytic Degradation of 4‐Chlorophenol in CeO ₂ Nanoparticles/Au/CeO ₂ Nanorods

The interband (d → sp) transition in the Au nanostructures of the CeO ₂ NP/Au/CeO ₂ NR (CAC) heterostructure enhances its photocatalytic efficiency for degrading 4‐chlorophenol (4‐CP) under UV light. Optical field simulations have revealed the presence of intense near‐field hotspots at the dual interfaces between Au and CeO ₂ , which play a critical role in augmenting the photocatalytic activity of this hybrid structure. Further, assessing the photoexcited charge carrier lifetimes has indicated excellent charge transfer efficiency at the CAC heterointerface that is ≈13 times higher than that observed at the CeO ₂ NP/CeO ₂ NR interface alone. This remarkable enhancement establishes the CAC heterostructure as a highly effective photocatalyst, achieving an impressive degradation performance of 85% for 4‐CP, characterized by a pseudofirst‐order rate constant of 0.014 min ⁻¹ . Radical scavenging experiments show that hydroxyl radicals ( ^• OH) are the primary reactive oxygen species responsible for the mineralization of 4‐CP. Here, the d‐band holes of Au serve as powerful oxidative centers that facilitate the efficient formation of ^• OH, driving the overall redox reactions. This study highlights the potential of Au–CeO ₂ hybrid nanostructures for high‐performance photocatalytic remediation of organic pollutants.